blob: 5a7a74cfde8d0441ddc839421aeb8c487cdfc3a7 [file] [log] [blame]
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package objabi
import (
"fmt"
"log"
"os"
"strings"
)
func envOr(key, value string) string {
if x := os.Getenv(key); x != "" {
return x
}
return value
}
var (
defaultGOROOT string // set by linker
GOROOT = envOr("GOROOT", defaultGOROOT)
GOARCH = envOr("GOARCH", defaultGOARCH)
GOOS = envOr("GOOS", defaultGOOS)
GO386 = envOr("GO386", defaultGO386)
GOARM = goarm()
GOMIPS = gomips()
GOMIPS64 = gomips64()
GOPPC64 = goppc64()
GOWASM = gowasm()
GO_LDSO = defaultGO_LDSO
Version = version
)
const (
ElfRelocOffset = 256
MachoRelocOffset = 2048 // reserve enough space for ELF relocations
)
func goarm() int {
def := defaultGOARM
if GOOS == "android" && GOARCH == "arm" {
// Android arm devices always support GOARM=7.
def = "7"
}
switch v := envOr("GOARM", def); v {
case "5":
return 5
case "6":
return 6
case "7":
return 7
}
// Fail here, rather than validate at multiple call sites.
log.Fatalf("Invalid GOARM value. Must be 5, 6, or 7.")
panic("unreachable")
}
func gomips() string {
switch v := envOr("GOMIPS", defaultGOMIPS); v {
case "hardfloat", "softfloat":
return v
}
log.Fatalf("Invalid GOMIPS value. Must be hardfloat or softfloat.")
panic("unreachable")
}
func gomips64() string {
switch v := envOr("GOMIPS64", defaultGOMIPS64); v {
case "hardfloat", "softfloat":
return v
}
log.Fatalf("Invalid GOMIPS64 value. Must be hardfloat or softfloat.")
panic("unreachable")
}
func goppc64() int {
switch v := envOr("GOPPC64", defaultGOPPC64); v {
case "power8":
return 8
case "power9":
return 9
}
log.Fatalf("Invalid GOPPC64 value. Must be power8 or power9.")
panic("unreachable")
}
type gowasmFeatures struct {
SignExt bool
SatConv bool
}
func (f gowasmFeatures) String() string {
var flags []string
if f.SatConv {
flags = append(flags, "satconv")
}
if f.SignExt {
flags = append(flags, "signext")
}
return strings.Join(flags, ",")
}
func gowasm() (f gowasmFeatures) {
for _, opt := range strings.Split(envOr("GOWASM", ""), ",") {
switch opt {
case "satconv":
f.SatConv = true
case "signext":
f.SignExt = true
case "":
// ignore
default:
log.Fatalf("Invalid GOWASM value. No such feature: " + opt)
}
}
return
}
func Getgoextlinkenabled() string {
return envOr("GO_EXTLINK_ENABLED", defaultGO_EXTLINK_ENABLED)
}
// HeaderString returns the toolchain configuration string written in
// Go object headers. This string ensures we don't attempt to import
// or link object files that are incompatible with each other. This
// string always starts with "go object ".
func HeaderString() string {
return fmt.Sprintf("go object %s %s %s X:%s\n", GOOS, GOARCH, Version, strings.Join(EnabledExperiments(), ","))
}